1. Field of the Invention
The invention relates to a speed control for an electric powered golf car, and more specifically relates to a control for smoothly starting the traction motor of a golf car by poviding time delayed power to the car motor. More particularly, the invention relates to a speed control which prevents directional movement changes (forward, reverse) at high speeds by automatically requiring the car to restart at its lowest speed.
2. Description of Related Art
Speed control devices for electric golf cars present certain difficulties during their use, particularly with respect to comfort. The predominate complaint is the inability of the car to ease into motion and thereafter, to accelerate gradually in speed. The driver and possible passenger in the vehicle typically experience lurching movements throughout the ride. Another problem encountered is the extensive maintenance required on the several drive components, i.e., differential, axles, wheel hubs, etc., due to the lurching movement or abrupt changes in speed. The lurching movement particularly occurs where the car is shifted from forward to reverse while driving the car at high speeds.
The prior art discloses various structures for attempting to control the speed of an electric powered vehicle. However, such structures provide various drawbacks and are different than the invention described herein.
For example, U.S. Pat. No. 3,912,978, issued to C. W. Poole on Oct. 14, 1975, describes a speed control for an electric vehicle, in which the speed of the vehicle is regulated by depressing a foot pedal which sequentially closes four switches depending upon the extent of depression of the foot pedal. The switches serve to activate relays for bypassing fixed resistors in order to vary the current flow to the motor for controlling its speed. U.S. Pat. No. 2,747,046, issued to E. F. Mekelberg on May 22, 1956, discloses a speed control for an electric truck in which a foot pedal is connected to a cam shaft which moves at a speed controlled by a dashpot timing assembly. As the cam shaft moves, a plurality of switches are operated to vary the current to the electric motor of the truck. Likewise, U.S. Pat. No. 2,267,381, issued to B. Ulinski on Dec. 23, 1941, discloses a speed control for use with an electric industrial truck. This patent teaches a control in which the operator must put the control in its first speed and keep it there for a short interval prior to going to other speeds. This is accomplished by utilizing a relay which has a slow operation requiring the a circuit to be maintained through a pair of first speed contacts for a predetermined period of time.